An organic electroluminescence device (hereinafter the term “electroluminescence” is often abbreviated as “EL”) is a self-emission device utilizing the principle that a fluorescent compound emits light by the recombination energy of holes injected from an anode and electrons injected from a cathode when an electric field is impressed.
Use of a polymer compound in an organic compound layer constituting an organic EL device has been studied since improvement in physical or thermal durability can be expected.
For examples, Patent Document 1 reports an organic EL device using, as a polymer, polyvinylcarbazole (PVCz) having hole-injecting capability. Since the glass transition temperature (Tg) of PVCz is very high, a thin film obtained using PVCz has improved stability, whereby an organic EL device with excellent durability can be fabricated. However, the driving voltage of this device is very high. In addition, this device had problems that luminous efficiency and life were not sufficient.
Patent Documents 2 discloses an organic EL device using a polymer obtained by copolymerizing a vinyl anthracene derivative and a vinyl carbazole derivative.
However, this device had a problem that luminous efficiency and life were not sufficient.
A polymer electroluminescence material has an advantage that a film can be formed by applying and printing the solution thereof, and hence various studies have been made (Patent Documents 3 to 7). However, an organic EL device using the above-mentioned polymer compound has a problem that device performance such as life (half life time) and luminous efficiency is not always sufficient.
Patent Document 1: JP-A-H02-223188
Patent Document 2: JP-A-H08-48726
Patent Document 3: JP-A-2005-272834
Patent Document 4: JP-A-2007-119763
Patent Document 5: JP-A-2007-162009
Patent Document 6: JP-A-2007-177225
Patent Document 7: WO2005/049546
The invention has been made to solve the above-mentioned problems, and an object thereof is to provide an organic EL device having a high luminous efficiency and a long life time and a compound which realizes such device.